Magnetic fabric: methods and applications — an introduction
Magnetic fabric: methods and applications — an introduction
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DOI：
10.1144/gsl.sp.2004.238.01.01
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
F. Martín-Hernández;C. M. Lüneburg;C. Aubourg;M. Jackson
中科院分区：
文献类型：
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作者：
F. Martín-Hernández;C. M. Lüneburg;C. Aubourg;M. Jackson
自Graham（1954）发表其开创性论文以来，已经过去了50年，该论文倡导使用磁化率各向异性（AMS）作为快速灵敏的岩石组构工具。在这50年中，Graham的“未充分利用”方法已成为标准，AMS和相关技术现在经常应用于表征各种地质材料中的组构（例如GEOREF数据库列出了500多篇以“磁各向异性”为关键词的期刊出版物）。磁各向异性作为岩石组构工具，因为大多数矿物的单个颗粒是磁各向异性的，即更容易在某些方向上磁化，这主要由晶体学和/或颗粒形状控制。在块体岩石尺度下的磁各向异性是由各向异性矿物颗粒的优选晶体取向（PCO）和/或优选尺寸取向（PDO）引起的。AMS也可能是由紧密间隔的强磁性颗粒之间的静磁相互作用引起的，这些颗粒不均匀地分布在更弱磁性的矿物基质中。在这两种情况下，磁各向异性与岩石组构的某些方面直接相关，因此它提供了一种快速，简单和有效的表征工具，即使磁组构和岩石组构之间的关系在细节上是相当复杂的。本论文集部分源自于在尼斯举行的EGS-AGU-EUG联合大会（2003年4月）关于磁组构的一次特别会议，该会议强调了最近的方法学进展、理论和实验研究以及岩石和沉积物中流动和变形组构的特征。在旧金山弗朗西斯科举行的AGU秋季会议（2003年12月）上的一次类似会议强调了
Fifty years have now passed since Graham (1954) published his seminal paper advocating the use of anisotropy of magnetic susceptibility (AMS) as a rapid and sensitive petrofabric tool. During these five decades, Graham’s ‘under-exploited’ method has become standard, and AMS and related techniques are now routinely applied to characterizing fabrics in a wide variety of geological materials (e.g. the GEOREF database lists over 500 journal publications with ‘magnetic anisotropy’ as keywords). Magnetic anisotropy works as a petrofabric tool because individual grains of most minerals are magnetically anisotropic, i.e. easier to magnetize in certain orientations, which are governed primarily by crystallography and/or grain shape. Magnetic anisotropy at the bulk rock scale results from the preferred crystallographic orientation (PCO) and/or preferred dimensional orientation (PDO) of anisotropic mineral grains. AMS can also result from magnetostatic interactions among closely spaced, strongly magnetic grains that are heterogeneously distributed in a matrix of more weakly magnetic minerals. In either case, magnetic anisotropy is directly related to some aspects of rock fabric, and thus it provides a quick, simple and effective characterization tool, even though the relationship between magnetic fabric and petrofabric is quite complex in detail. The present collection of papers originated, in part, at a special session on magnetic fabrics at the Joint Assembly of the EGS-AGU-EUG (April 2003) in Nice, which highlighted recent methodological advances, theoretical and experimental studies, and characterization of flow and deformation fabrics in rocks and sediments. A similar session at the AGU Fall Meeting (December 2003) in San Francisco underscored the continuing breadth